Method and structure for securing a monitoring device element

ABSTRACT

Structures and methods for attaching a device to a user&#39;s skin are provided. Embodiments include refreshing an adhesive attaching an element of an analyte monitoring device so that a first adhesive attaches the element of the analyte monitoring device during a first time period and a second adhesive attaches the element of the analyte monitoring device to the user&#39;s skin during a second time period. A sensor remains at least partially inserted into the user&#39;s while the refreshing of the adhesive from the first to the second adhesive occurs.

RELATED APPLICATION

The present application claims priority under §35 U.S.C. 119(e) to U.S.provisional application No. 60/946,492 filed Jun. 27, 2007 entitled“Method and Structure for Securing a Monitoring Device Element,” andassigned to the assignee of the present application, Abbott DiabetesCare Inc. of Alameda, Calif., the disclosure of which is incorporated byreference for all purposes.

BACKGROUND

The detection of the level of analytes, such as glucose, lactate,oxygen, and the like, in certain individuals is vitally important totheir health. For example, the monitoring of glucose is particularlyimportant to individuals with diabetes. Diabetics may need to monitorglucose levels to determine when insulin is needed to reduce glucoselevels in their bodies or when additional glucose is needed to raise thelevel of glucose in their bodies.

Devices have been developed for continuous or automatic monitoring ofanalytes, such as glucose, in bodily fluid such as in the blood streamor in interstitial fluid. Some of these analyte measuring devices areconfigured so that at least a portion of the devices are positionedbelow a skin surface of a user, e.g., in a blood vessel or in thesubcutaneous tissue of a user.

The user's comfort and the range of activities that may be performedwhile a portion of the device is positioned below a skin surface areimportant considerations in designing extended-use sensors forcontinuous or automatic in vivo monitoring of the level of an analyte,such as glucose. There is a need for a small, comfortable device whichmay continuously monitor the level of an analyte, such as glucose, whilestill permitting the user to engage in normal activities. Continuousand/or automatic monitoring of the analyte may provide a warning to theuser when the level of the analyte is at or near a threshold level. Forexample, if glucose is the analyte, then the monitoring device might beconfigured to warn the user of current or impending hyperglycemia orhypoglycemia. The user may then take appropriate actions.

One of the challenges associated with producing an effective andcomfortable monitoring device is securing an element of the monitoringdevice to the skin. A monitoring device element may be attached to theskin with an adhesive. However, adhesives eventually lose their adhesiveproperties. Also, outer layers of the skin continually slough off.Eventually, the loss of adhesion and sloughing off of the skin serve todetach the monitoring device element from the skin and the monitoringdevice element falls off of the user.

When the monitoring device element falls off of the skin, a newmonitoring device element may have to be attached to the skin and a newsensor may have to be inserted into the skin. Accordingly, if amonitoring device falls off too quickly, its life is limited and a usermust insert another sensor, adding to the cost of the monitoring device.Also, the more frequent insertions of sensors may cause skin trauma.

One manner of increasing the attachment time is to provide a strongeradhesive. However, increasing the strength of the adhesive makes removalof the monitoring device element from the skin more difficult andpainful. Also, simply increasing the adhesive strength may not overcomethe problems associated with outer layers of skin sloughing off thebody. Accordingly, the present disclosure is directed to providing astructure and method of attaching an element of a monitoring device to auser's skin that will result in a longer-lasting attachment.

SUMMARY

Provided are methods and structures for securing an element of amonitoring device to a person's skin. In one embodiment a first adhesiveis used to secure the element to a person's skin during a first timeperiod and a second adhesive is used to secure the element to theperson's skin during a second time period. A sensor may be at leastpartially inserted into the user's skin during the first and the secondtime periods and the element may include a housing for the sensor.

BRIEF DESCRIPTION OF THE DRAWINGS

The above aspects and features of the present disclosure will be moreapparent by describing certain embodiments of the present disclosurewith reference to the accompanying drawings, in which:

FIG. 1 is a block diagram of an exemplary embodiment of a datamonitoring and management system according to the present disclosure;

FIG. 2 shows a schematic diagram of an embodiment of an analyte sensoraccording to the present disclosure; and

FIGS. 3A-3B show a perspective view and a cross sectional view,respectively of another embodiment of an analyte sensor.

FIG. 4 is a perspective view of an exemplary embodiment of an on-skinsensor unit, according to the disclosure;

FIG. 5 is a top view of a cover of the on-skin sensor unit of FIG. 4;

FIG. 6 is bottom view of an on-skin sensor unit with adhesives accordingto an exemplary embodiment of the present disclosure;

FIG. 7 is a side view of the on-skin sensor unit of FIG. 6;

FIG. 8 is a side view of the on-skin sensor unit of FIG. 6 attached to auser's skin during a first time period;

FIG. 9 is a side view of the on-skin sensor unit of FIG. 6 attached to auser's skin during a second time period;

FIG. 10 is a side view of an on-skin sensor unit with adhesivesaccording to another exemplary embodiment of the present disclosure andattached to a user's skin during a first time period;

FIG. 11 is a side view of the on-skin sensor unit with adhesives of FIG.10 and attached to a user's skin during a second time period;

FIG. 12 is a side view of an on-skin sensor unit with adhesivesaccording to another exemplary embodiment of the present disclosure andattached to a user's skin during a first time period;

FIGS. 13A and 13B are side and perspective views, respectively, of theon-skin sensor unit with adhesives shown in FIG. 12 with a portion ofthe control unit lifted from the user's skin;

FIG. 14 is a bottom view of an on-skin sensor unit with adhesivesaccording to an exemplary embodiment of the present disclosure;

FIG. 15 is a side view of an on-skin sensor unit with an adhesiveaccording to an exemplary embodiment of the present disclosure.

FIG. 16 is a side view of an on-skin sensor unit with a plurality ofmicroneedles according to an exemplary embodiment of the presentdisclosure.

DETAILED DESCRIPTION

Before the present disclosure is described, it is to be understood thatthis disclosure is not limited to particular embodiments described, assuch may, of course, vary. It is also to be understood that theterminology used herein is for the purpose of describing particularembodiments only, and is not intended to be limiting, since the scope ofthe present disclosure will be limited only by the appended claims.

Where a range of values is provided, it is understood that eachintervening value, to the tenth of the unit of the lower limit unlessthe context clearly dictates otherwise, between the upper and lowerlimit of that range and any other stated or intervening value in thatstated range, is encompassed within the disclosure. The upper and lowerlimits of these smaller ranges may independently be included in thesmaller ranges as also encompassed within the disclosure, subject to anyspecifically excluded limit in the stated range. Where the stated rangeincludes one or both of the limits, ranges excluding either or both ofthose included limits are also included in the disclosure.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this disclosure belongs. Although any methods andmaterials similar or equivalent to those described herein may also beused in the practice or testing of the present disclosure, the preferredmethods and materials are now described.

It must be noted that as used herein and in the appended claims, thesingular forms “a”, “an”, and “the” include plural referents unless thecontext clearly dictates otherwise.

As will be apparent to those of skill in the art upon reading thisdisclosure, each of the individual embodiments described and illustratedherein has discrete components and features which may be readilyseparated from or combined with the features of any of the other severalembodiments without departing from the scope or spirit of the presentdisclosure.

The figures shown herein are not necessarily drawn to scale, with somecomponents and features being exaggerated for clarity.

Embodiments include analyte monitoring devices and systems that includean analyte sensor—at least a portion of which is positionable beneaththe skin of the user—for the in vivo detection, of an analyte, such asglucose, lactate, and the like, in a body fluid. Embodiments includewholly implantable analyte sensors and analyte sensors in which only aportion of the sensor is positioned under the skin and a portion of thesensor resides above the skin, e.g., for contact to a transmitter,receiver, transceiver, processor, etc. The sensor may be, for example,subcutaneously positionable in a user for the continuous or periodicmonitoring of a level of an analyte in a user's interstitial fluid. Forthe purposes of this description, continuous monitoring and periodicmonitoring will be used interchangeably, unless noted otherwise. Thesensor response may be correlated and/or converted to analyte levels inblood or other fluids. In certain embodiments, an analyte sensor may bepositioned in contact with interstitial fluid to detect the level ofglucose, which detected glucose may be used to infer the glucose levelin the user's bloodstream. Analyte sensors may be insertable into avein, artery, or other portion of the body containing fluid. Embodimentsof the analyte sensors of the subject disclosure may be configured formonitoring the level of the analyte over a time period which may rangefrom minutes, hours, days, weeks, or longer.

Of interest are analyte sensors, such as glucose sensors, that arecapable of in vivo detection of an analyte for about one hour or more,e.g., about a few hours or more, e.g., about a few days or more, e.g.,about three days or more, e.g., about five days or more, e.g., aboutseven days or more, e.g., about several weeks or at least one month.Future analyte levels may be predicted based on information obtained,e.g., the current analyte level at time t0, the rate of change of theanalyte, etc. Predictive alarms may notify the user of predicted analytelevels that may be of concern in advance of the user's analyte levelreaching the future level. This provides the user an opportunity to takecorrective action.

Embodiments described herein are applicable to attaching a device to aperson's skin. As noted above, the exemplary embodiments describedherein relate to attaching to a user's skin an element of an analytemonitoring system using an implantable sensor for the in vivodetermination of a concentration of an analyte, such as glucose orlactate, in a fluid. However, although certain exemplary embodimentsdescribe an analyte monitoring system, the disclosure is not limited tothe particular system described herein. The structure and method of thepresent disclosure may be applied to other devices and particularly todevices adapted to be secured to a person's skin and also devices whichinclude a sensor which is at least partially inserted into the person'sskin.

FIG. 1 shows a data monitoring and management system such as, forexample, an analyte (e.g., glucose) monitoring system 100 in accordancewith certain embodiments. Embodiments of the subject disclosure arefurther described primarily with respect to glucose monitoring devicesand systems, and methods of glucose detection, for convenience only andsuch description is in no way intended to limit the scope of thedisclosure. It is to be understood that the analyte monitoring systemmay be configured to monitor a variety of analytes at the same time orat different times.

Analytes that may be monitored include, but are not limited to, acetylcholine, amylase, bilirubin, cholesterol, chorionic gonadotropin,creatine kinase (e.g., CK-MB), creatine, creatinine, DNA, fructosamine,glucose, glutamine, growth hormones, hormones, ketone bodies, lactate,peroxide, prostate-specific antigen, prothrombin, RNA, thyroidstimulating hormone, and troponin. The concentration of drugs, such as,for example, antibiotics (e.g., gentamicin, vancomycin, and the like),digitoxin, digoxin, drugs of abuse, theophylline, and warfarin, may alsobe monitored. In those embodiments that monitor more than one analyte,the analytes may be monitored at the same or different times.

The analyte monitoring system 100 includes a sensor unit 101, a dataprocessing unit 102 connectable to the sensor unit 101, and a primaryreceiver unit 104 which is configured to communicate with the dataprocessing unit 102 via a communication link 103. In certainembodiments, the primary receiver unit 104 may be further configured totransmit data to a data processing terminal 105 to evaluate or otherwiseprocess or format data received by the primary receiver unit 104. Thedata processing terminal 105 may be configured to receive data directlyfrom the data processing unit 102 via a communication link which mayoptionally be configured for bi-directional communication. Further, thedata processing unit 102 may include a transmitter or a transceiver totransmit and/or receive data to and/or from the primary receiver unit104 and/or the data processing terminal 105 and/or optionally thesecondary receiver unit 106.

Also shown in FIG. 1 is an optional secondary receiver unit 106 which isoperatively coupled to the communication link and configured to receivedata transmitted from the data processing unit 102. The secondaryreceiver unit 106 may be configured to communicate with the primaryreceiver unit 104, as well as the data processing terminal 105. Thesecondary receiver unit 106 may be configured for bi-directionalwireless communication with each of the primary receiver unit 104 andthe data processing terminal 105. As discussed in further detail below,in certain embodiments the secondary receiver unit 106 may be ade-featured receiver as compared to the primary receiver, i.e., thesecondary receiver may include a limited or minimal number of functionsand features as compared with the primary receiver unit 104. As such,the secondary receiver unit 106 may include a smaller (in one or more,including all, dimensions), compact housing or embodied in a device suchas a wrist watch, arm band, etc., for example. Alternatively, thesecondary receiver unit 106 may be configured with the same orsubstantially similar functions and features as the primary receiverunit 104. The secondary receiver unit 106 may include a docking portionto be mated with a docking cradle unit for placement by, e.g., thebedside for night time monitoring, and/or a bi-directional communicationdevice. A docking cradle may recharge a powers supply.

Only one sensor unit 101, data processing unit 102 and data processingterminal 105 are shown in the embodiment of the analyte monitoringsystem 100 illustrated in FIG. 1. However, it will be appreciated by oneof ordinary skill in the art that the analyte monitoring system 100 mayinclude more than one sensor unit 101 and/or more than one dataprocessing unit 102, and/or more than one data processing terminal 105.Multiple sensors may be positioned in a user for analyte monitoring atthe same or different times. In certain embodiments, analyte informationobtained by a first positioned sensor may be employed as a comparison toanalyte information obtained by a second sensor. This may be useful toconfirm or validate analyte information obtained from one or both of thesensors. Such redundancy may be useful if analyte information iscontemplated in critical therapy-related decisions. In certainembodiments, a first sensor may be used to calibrate a second sensor.

The analyte monitoring system 100 may be a continuous monitoring system,or semi-continuous, or a discrete monitoring system. In amulti-component environment, each component may be configured to beuniquely identified by one or more of the other components in the systemso that communication conflict may be readily resolved between thevarious components within the analyte monitoring system 100. Forexample, unique IDs, communication channels, and the like, may be used.

In certain embodiments, the primary receiver unit 104 may include ananalog interface section including an RF receiver and an antenna that isconfigured to communicate with the data processing unit 102 via thecommunication link 103, and a data processing section for processing thereceived data from the data processing unit 102 such as data decoding,error detection and correction, data clock generation, data bitrecovery, etc., or any combination thereof.

In operation, the primary receiver unit 104 in certain embodiments isconfigured to synchronize with the data processing unit 102 to uniquelyidentify the data processing unit 102, based on, for example, anidentification information of the data processing unit 102, andthereafter, to periodically receive signals transmitted from the dataprocessing unit 102 associated with the monitored analyte levelsdetected by the sensor unit 101.

Referring again to FIG. 1, the data processing terminal 105 may includea personal computer, a portable computer such as a laptop or a handhelddevice (e.g., personal digital assistants (PDAs), telephone such as acellular phone (e.g., a multimedia and Internet-enabled mobile phonesuch as an iPhone or similar phone), mp3 player, pager, and the like),drug delivery device, each of which may be configured for datacommunication with the receiver via a wired or a wireless connection.Additionally, the data processing terminal 105 may further be connectedto a data network (not shown) for storing, retrieving, updating, and/oranalyzing data corresponding to the detected analyte level of the user.

The data processing terminal 105 may include an infusion device such asan insulin infusion pump or the like, which may be configured toadminister insulin to users, and which may be configured to communicatewith the primary receiver unit 104 for receiving, among others, themeasured analyte level. Alternatively, the primary receiver unit 104 maybe configured to integrate an infusion device therein so that theprimary receiver unit 104 is configured to administer insulin (or otherappropriate drug) therapy to users, for example, for administering andmodifying basal profiles, as well as for determining appropriate bolusesfor administration based on, among others, the detected analyte levelsreceived from the data processing unit 102. An infusion device may be anexternal device or an internal device (wholly implantable in a user).

In certain embodiments, the data processing terminal 105, which mayinclude an insulin pump, may be configured to receive the analytesignals from the data processing unit 102, and thus, incorporate thefunctions of the primary receiver unit 104 including data processing formanaging the user's insulin therapy and analyte monitoring. In certainembodiments, the communication link 103 as well as one or more of theother communication interfaces shown in FIG. 1, may use one or more of:an RF communication protocol, an infrared communication protocol, aBluetooth® enabled communication protocol, an 802.11x wirelesscommunication protocol, or an equivalent wireless communication protocolwhich would allow secure, wireless communication of several units (forexample, per HIPAA requirements), while avoiding potential datacollision and interference.

FIG. 2 schematically shows an embodiment of an analyte sensor inaccordance with the present disclosure. This sensor embodiment includeselectrodes 401, 402 and 403 on a base 404. Electrodes (and/or otherfeatures) may be applied or otherwise processed using any suitabletechnology, e.g., chemical vapor deposition (CVD), physical vapordeposition, sputtering, reactive sputtering, printing, coating, ablating(e.g., laser ablation), painting, dip coating, etching, and the like.Materials include but are not limited to aluminum, carbon (such asgraphite), cobalt, copper, gallium, gold, indium, iridium, iron, lead,magnesium, mercury (as an amalgam), nickel, niobium, osmium, palladium,platinum, rhenium, rhodium, selenium, silicon (e.g., dopedpolycrystalline silicon), silver, tantalum, tin, titanium, tungsten,uranium, vanadium, zinc, zirconium, mixtures thereof, and alloys,oxides, or metallic compounds of these elements.

The sensor may be wholly implantable in a user or may be configured sothat only a portion is positioned within (internal) a user and anotherportion outside (external) a user. For example, the sensor 400 mayinclude a portion positionable above a surface of the skin 410, and aportion positioned below the skin. In such embodiments, the externalportion may include contacts (connected to respective electrodes of thesecond portion by traces) to connect to another device also external tothe user such as a transmitter unit. While the embodiment of FIG. 2shows three electrodes side-by-side on the same surface of base 404,other configurations are contemplated, e.g., fewer or greaterelectrodes, some or all electrodes on different surfaces of the base orpresent on another base, some or all electrodes stacked together,electrodes of differing materials and dimensions, etc.

FIG. 3A shows a perspective view of an embodiment of an electrochemicalanalyte sensor 500 having a first portion (which in this embodiment maybe characterized as a major portion) positionable above a surface of theskin 510, and a second portion (which in this embodiment may becharacterized as a minor portion) that includes an insertion tip 530positionable below the skin, e.g., penetrating through the skin andinto, e.g., the subcutaneous space 520, in contact with the user'sbiofluid such as interstitial fluid. Contact portions of a workingelectrode 501, a reference electrode 502, and a counter electrode 503are positioned on the portion of the sensor 500 situated above the skinsurface 510. Working electrode 501, a reference electrode 502, and acounter electrode 503 are shown at the second section and particularlyat the insertion tip 530. Traces may be provided from the electrode atthe tip to the contact, as shown in FIG. 3A. It is to be understood thatgreater or fewer electrodes may be provided on a sensor. For example, asensor may include more than one working electrode and/or the counterand reference electrodes may be a single counter/reference electrode,etc.

FIG. 3B shows a cross sectional view of a portion of the sensor 500 ofFIG. 3A. The electrodes 501, 502 and 503, of the sensor 500 as well asthe substrate and the dielectric layers are provided in a layeredconfiguration or construction. For example, as shown in FIG. 3B, in oneaspect, the sensor 500, includes a substrate layer 504, and a firstconducting layer 501 such as carbon, gold, etc., disposed on at least aportion of the substrate layer 504, and which may provide the workingelectrode. Also shown disposed on at least a portion of the firstconducting layer 501 is a sensing layer 508.

A first insulation layer such as a first dielectric layer 505 isdisposed or layered on at least a portion of the first conducting layer501, and further, a second conducting layer 509 may be disposed orstacked on top of at least a portion of the first insulation layer (ordielectric layer) 505. As shown in FIG. 3B, the second conducting layer509 may provide the reference electrode 502, and in one aspect, mayinclude a layer of silver/silver chloride (Ag/AgCl), gold, etc.

A second insulation layer 506 such as a dielectric layer in oneembodiment may be disposed or layered on at least a portion of thesecond conducting layer 509. Further, a third conducting layer 503 mayprovide the counter electrode 503. It may be disposed on at least aportion of the second insulation layer 506. Finally, a third insulationlayer may be disposed or layered on at least a portion of the thirdconducting layer 503. In this manner, the sensor 500 may be layered suchthat at least a portion of each of the conducting layers is separated bya respective insulation layer (for example, a dielectric layer). Theembodiment of FIGS. 3A and 3B show the layers having different lengths.Some or all of the layers may have the same or different lengths and/orwidths.

In certain embodiments, some or all of the electrodes 501, 502, 503 maybe provided on the same side of the substrate 504 in the layeredconstruction as described above, or alternatively, may be provided in aco-planar manner such that two or more electrodes may be positioned onthe same plane (e.g., side-by side (e.g., parallel) or angled relativeto each other) on the substrate 504. For example, co-planar electrodesmay include a suitable spacing there between and/or include dielectricmaterial or insulation material disposed between the conductinglayers/electrodes. Furthermore, in certain embodiments, one or more ofthe electrodes 501, 502, 503 may be disposed on opposing sides of thesubstrate 504. In such embodiments, contact pads may be on the same ordifferent sides of the substrate. For example, an electrode may be on afirst side and its respective contact may be on a second side, e.g., atrace connecting the electrode and the contact may traverse through thesubstrate.

The description herein is directed primarily to electrochemical sensorsfor convenience only and is in no way intended to limit the scope of thedisclosure. Other sensors and sensor systems are contemplated. Suchinclude, but are not limited to, optical sensors, calorimetric sensors,and sensors that detect hydrogen peroxide to infer glucose levels, etc.The sensor may be used as part of the sensor unit 101.

At least some portions of the analyte monitoring system 100 may beattached on a user's skin. Exemplary embodiments of the presentdisclosure are described with reference to the sensor unit 101 and thedata processing unit 102 being attached to a user's skin. However, otherparts of the analyte monitoring system 100 may additionally oralternatively be attached to a user's skin

FIGS. 4 and 5 show, respectively, an exemplary embodiment of a sensorunit 101 and a data processing unit 102 which can be coupled to a mountof the sensor unit 101. As shown in FIG. 4, there is a sensormount/housing 45 which stays on a user's skin after the sensor isinserted into the user's skin. The sensor mount 45 holds the sensor 42in place and holds the data processing unit/transmitter 102. An adhesiveportion 5 is provided on the bottom of the sensor mount 45. As shown inFIG. 5, the data processing unit 102 of the exemplary embodiment is awireless transmitter. The unit 102 includes tabs and guides which allowthe unit 102 to slide into the mount 45 and hold the transmitter 102 inplace. Additionally, the transmitter unit 102 comprises contact points80 which connect the sensor 42 to the transmitter. Together, these unitsprovide an on-skin unit 44.

The on-skin unit 44 may be formed in a shape that is comfortable to theuser and which may permit concealment, for example, under a user'sclothing. The thigh, leg, upper arm, shoulder, or abdomen are convenientparts of the user's body for placement of the on-skin sensor unit 44 tomaintain concealment. However, the on-skin unit 44 may be positioned onother portions of the user's body. One embodiment of the on-skin sensorunit 44 has a generally rectangular shape to enhance concealment, asillustrated in FIGS. 4 and 5. However, other shapes and sizes, such as athin oval shape, may be used.

The particular profile, as well as the height, width, length, weight,and volume of the on-skin unit 44 may vary and depends, at least inpart, on the components and associated functions included in the on-skinsensor unit 44, as discussed below. For example, in some embodiments,the on-skin unit 44 may have a height of about 2 cm or less, 1.3 cm orless, or about 0.7 cm or less. In some embodiments, the on-skin unit 44may have a weight of about 90 grams or less, e.g., about 45 grams orless, e.g., about 25 grams or less. In some embodiments, the on-skinunit 44 has a volume of about 15 cm³ or less.

The sensor mount 45, illustrated in FIGS. 4 and 5, may be formed using avariety of materials, including, for example, plastic and polymericmaterials, particularly rigid thermoplastics and engineeringthermoplastics. Suitable materials include, for example, polyvinylchloride, polyethylene, polypropylene, polystyrene, ABS polymers, andcopolymers thereof. The mount 45 may be formed using a variety oftechniques including, for example, injection molding, compressionmolding, casting, and other molding methods. Hollow or recessed regionsmay be formed in the sensor mount 45 of the on-skin unit 44. Theelectronic components of the on-skin unit 44, described below, and/orother items, such as a battery or a speaker for an audible alarm, may beplaced in the hollow or recessed areas.

Conductive contacts 80 may be formed on the exterior of the transmitter102 which connect to the sensor 42.

FIGS. 6 and 7 show exemplary embodiments of the sensor unit with aplurality of discrete adhesive portions on a surface, e.g., a bottom ofthe sensor mount 45 for securing the on-skin unit 44 to a user's skin.FIG. 6 is a bottom view of the on-skin unit 44 and FIG. 7 is across-sectional side view of the on-skin unit 44. The sizes of theadhesive portions may be exaggerated in the drawings for purposes ofexplanation.

As shown in FIGS. 6 and 7, a first adhesive 1 and a second adhesive 2are provided on a bottom of the sensor mount 45. The first adhesive 1 isused to secure the on-skin unit 44 to the user's skin during a firsttime period and the second adhesive 2 is used to secure the on-skin unit44 to the user's skin during a second time period. During the secondtime period, the first adhesive may remain on the on-skin unit 44 andwork with the second adhesive or may be removed to expose the base ofthe sensor mount 45.

As shown in FIGS. 6 and 7, removable coverings 3 cover the secondadhesive 2 and optional protrusions 4 are attached to the removablecovering 3. The protrusions are used to help remove the coverings 3 andexpose a surface of the second adhesive 2. Since the protrusions 4 areattached to the coverings 3, pulling on the protrusions 4 removes thecoverings 3. The protrusions 4 may be thin strings. However, theprotrusions are not limited to thin strings, and other materials may beused to form the protrusions 4. As shown in FIG. 6, a tab 5 may beattached to the protrusions 4. The tab 5 allows for all of the coverings3 to be removed at once by pulling on the tab 5, rather than theindividual protrusions 4. The unit 44 remains on the user's skin duringthe time that the second adhesive 2 is uncovered and used forattachment.

As noted above, after the second adhesive is exposed for securing theon-skin unit 44, the first adhesive 1 may also be removed. Accordingly,for example as shown in FIG. 6, protrusions 4 (or other contacts) ifprovided may also be attached to the first adhesive 1. These protrusions4 may also be attached to a tab 5 for easier removal.

In FIGS. 6 and 7, the first and second adhesives are patterned in theform of alternating stripes. This configuration allows for a generallyuniform distribution of the first and second adhesive 1, 2. Thisconfiguration also allows for the coverings 3 of the second adhesive tobe removed without disturbing the first adhesive 1. Also, it allows thefirst adhesive 1 to be removed without disturbing the second adhesive.The adhesives may be arranged in other configurations as well. Forexample, other configurations include, but are not limited to, dots,intersecting stripes, etc.

FIGS. 8 and 9 illustrate a method of using of the adhesive structure ofFIGS. 6 and 7 to attach the on-skin unit 44 to a user's skin accordingto certain embodiments. As shown in FIG. 8, initially the first adhesiveis exposed and the second adhesive is covered by coverings 3. The firstadhesive thus secures the sensor to the skin S (FIGS. 10-13B) of a userfor a first time period. This time period may be any suitable period,e.g., approximately three days or longer, e.g., approximately five daysor longer, e.g., approximately seven days or longer, although theduration is not particularly limited and may be substantially longer orshorter than about three days.

At the end of the first time period, the coverings 3 are removed. Thismay be done by pulling on the individual protrusions 4 or, if included,by pulling on a tab 5 attached to each of the protrusions 4. Thecoverings 3 may also be removed in other manners which do not requirethe protrusions 4 or tab 5. When the coverings 3 are removed, the secondadhesive 2 is exposed to contact the skin, and may be pressed on theskin S to maintain contact if necessary. During the removal of thecovering 3 and the pressing of the second adhesive, the sensor 42remains at least partially inserted into the user's skin S, i.e.,remains in analyte monitoring position. While the coverings 3 are beingremoved, the first adhesive may continue to secure the sensor mount 45to the user's skin.

As shown in FIG. 9, after the coverings 3 are removed, the on-skin unit44 may be pressed against the skin so that the fresh second adhesive 2attaches to the user's skin. The second adhesive 2 then secures thesensor unit to the user's skin for a second time period. Again, thissecond time period is not particularly limited, but may be analogous tothat described above of the first time period. The user may remove thesensor at the end of a specified second time period, or the on-skin unit44 may simply remain on the user's skin until it falls off. In certainembodiments, third, fourth, fifth, . . . adhesives may be included andthe process may be repeated as appropriate to extend the adhesion timeto the skin.

As shown in FIG. 9, after the second adhesive 2 is exposed and helpssecure the on-skin unit 44 to the skin S, the first adhesive may beremoved by the protrusions 4 and tab 5 described above. Alternatively,the first adhesive 1 may simply remain on the on-skin unit 44 during thesecond time period. If the first adhesive 1 remains on the sensor mount45, it may work in conjunction with the second adhesive 2 during thesecond time period.

Accordingly, according to the exemplary embodiment of FIGS. 8 and 9, theadhesive used to secure the on-skin unit 44 may be refreshed or renewedwithout removing the sensor 42 from a user's skin. Because the adhesiveis refreshed, the on-skin unit 44 may remain on the user's skin for alonger period of time without using an unnecessarily strong adhesive.This may increase the life of the on-skin unit 44 and the sensor 42 andmay avoid unnecessary trauma to the skin by excessive insertion of thesensor 42. Also, it may avoid the inconvenience for the user of havingto frequently replace the sensor 42 and on-skin unit 44. The use of themultiple adhesives as described in the exemplary embodiment may alsodecrease the chances of an adverse reaction to the adhesives, since theadhesive site may be changed between the use of the first and secondadhesives.

The first adhesive 1 and the second adhesive 2 may be the same adhesivematerial or may be different adhesives, same or different shape, size,etc. Also, they may have the same or different strengths. For example,the first adhesive 1 may be made stronger to ensure that the sensormount 45 does not fall off before the user exposes the second adhesive2. The second adhesive may be made less strong so that the user maycomfortably remove the sensor unit from the skin at the end of thesecond time period.

FIGS. 10 and 11 illustrate another exemplary embodiment of an on-skinunit 44 attachment method and structure. FIG. 10 is a side view of theon-skin unit 44 in a first configuration during a first time period.Like the previous exemplary embodiment, there is both a first adhesive 1and a second adhesive 2. The first adhesive 1 secures the on-skin unit44 to the user's skin S during the first period and a fresh secondadhesive 2 is used during a second time period. As shown in FIG. 10,during the first time period, the first adhesive 1 is at a lowerposition so that it may contact the user's skin S and secure the sensormount 45. As shown in FIG. 11, after the first period, the secondadhesive 2 is moved to a position of contacting the skin and securingthe sensor unit. This may occur by switching the positions of the firstand second adhesives. Alternatively, the first adhesive 1 may beremoved. In any event, there may be a covering over the second adhesive2 which is removed before it is contacted with the skin S.

The positions of the first and second adhesives may be changed in avariety of different ways. One possible manner is to use a cam to pressthe areas of the first adhesives down during the first time period andthe second adhesives down during a second time period. The areas of thesensor mount 45 may be biased in the upward direction. Accordingly, whenthe cam is in a position of pressing areas corresponding to the first orsecond adhesive downwardly, the pressed areas move downward. When thefirst or second adhesive is not pressed downward by a portion of thecam, the adhesive returns up. Alternatively, the areas on which thefirst and second adhesives are mounted may simply be mechanicallydrivable up and down, but the turning of a gear or the like. Mechanicalmethods may include a simple press-down on either side of the devicewith a 2 pronged fork or a twisting action to rotate an axle between awheel/cylinder at either end of the device, resembling the turn of akey. The motion may also be accomplished in an electrical manner whichprovides similar mechanical movement powered automatically by anattached motor. Other mechanical and electrical methods for moving thefirst and second adhesives are also possible.

FIGS. 12, 13A and 13B show another exemplary embodiment of thedisclosure. According to this exemplary embodiment, a first adhesive 1and a second adhesive 2 are layered on the bottom of the on-skin unit44. During the first time period, the sensor 42 is at least partiallyinserted into the skin S and the sensor mount 45 of the sensor unit issecured to the skin S by the first adhesive 1. In this exemplaryembodiment, the on-skin unit 44 includes a hinge 7. The hinge allows ahinged portion 51 of the on-skin unit 44 to be hingedly rotated around asensor portion 50 of the on-skin unit 44. As shown in FIG. 13A, afterthe first time period (e.g., three days) has passed, hinge portion 51may be rotated around the hinge 7. The sensor portion 50, which includesthe sensor 42 remains in the same location as the hinged portion 51 islifted. Thus, the sensor 42 may remain in the skin and functioningduring this time. After the hinged portion 51 is lifted, the firstadhesive 1 is removed and the second adhesive 2 is exposed. In FIG. 13B,the hinged portion 51 is drawn in shadow to illustrate the hinge 7 infurther detail. As shown in FIG. 13B, in this exemplary embodiment ofthe hinge 7, one leaf is attached to the sensor portion 50 and anotherleaf is attached to the hinged portion 51 and the leaves are connectedat a corner portion of the sensor and hinge portions 50, 51 to allow thehinged portion 51 to rotate away from the user's skin relative to thesensor portion 50. The disclosure is not limited to the hinge shown inFIG. 13B and other types of hinges and manners of hinging the hingedportion 51 to the sensor portion 50 may also be used.

In this exemplary embodiment, a partition 8 is located between the firstadhesive 1 and the second adhesive 2. The partition 8 separates thefirst 1 and second adhesive 2. The partition 8 also serves as a coveringfor the second adhesive 2. Removing the partition 8 peels off the firstlayer of adhesive 1 and exposes the second layer of adhesive 2. Thehinged portion 51 may then be swiveled back around the hinge 7 so thatthe second adhesive 2 contacts the skin S and secures the on-skin unit44. In this manner, the adhesive securing the on-skin unit 44 isrefreshed without disturbing the sensor 42.

Additionally, as shown in FIGS. 12, 13A and 13B, there may be an areawith no adhesive at an edge of the hinged portion. This area of noadhesive helps to allow the hinged portion 51 to swivel away from theskin S.

The on-skin unit 44 may be hinged and swiveled in various directions.For example, instead of or in addition to being lifted vertically awayfrom the skin, the hinged portion 51 may be rotated around the sensor42. Rotating the location of the hinged portion 51 allows the secondadhesive 2 to be attached to a fresh site, at least partially differentthan the area of skin to which the first adhesive 1 was attached. Thishelps to alleviate some of the problems associated with the sloughingoff of skin and may also prevent problems associated with an adverseskin reaction to the adhesive by lessening the time that the adhesive isattached to a particular area of the skin.

Also, a sensor area adhesive 9 may be provided around the sensor 42 atthe sensor portion 50. The insertion of the sensor 42 itself provides atleast some attachment to the skin. Also, the sensor 42 may be providedwith a barb or other structure to increase its attachment in the skin S.The sensor area adhesive 9 provides an additional degree of attachmentof the sensor portion 50 to the skin so that when the hinged portion 51is being swiveled, the sensor does not fall out of the user's skin. Thesensor area adhesive 9 may be stronger than the first and secondadhesives. Particularly, the sensor area adhesive 9 may be designed toeffectively last throughout the first and second time periods, or atleast through the first time period and the swiveling of the hinged part51.

The first and second adhesives 1, 2 may be either solid or formed in apattern such as stripes or concentric circles. Also, the first andsecond adhesives may be the same adhesive or different adhesives. Forexample, the first adhesive 1 may be made stronger than the secondadhesive 2 to ensure that it lasts until the user exposes and uses thesecond adhesive 2. Alternatively, the first adhesive 1 may be made lessstrong so that the user may swivel the on-skin unit 44 away from theskin S.

According to another exemplary embodiment, shown in FIG. 14, first andsecond adhesives 1, 2 are patterned on the bottom of the on-skin unit 44and are used at the same time to secure the on-skin unit 44 to theuser's skin. In this exemplary embodiment, the first and secondadhesives have different strengths and/or other properties. For example,the first adhesive 1 may be stronger than the second adhesive 2. Thestrong first adhesive would ensure that the sensor mount 45 is stronglybonded to the user's skin while the second adhesive 2 would also providesome assistance in securing the on-skin unit 44, but would also balancecomfort in removal. Accordingly, this exemplary embodiment balances thecharacteristics of the first adhesive 1 and the second adhesive 2.

The first and second adhesives 1, 2 may be arranged in a striped manner.Another possibility is to arrange the first and second adhesives 1, 2 ina pattern of concentric circles, as shown in FIG. 14. These two patternswould allow a relatively good mixing and spacing of the two differentadhesives. However, the disclosure is not limited to these two patterns.

FIG. 15 illustrates another exemplary embodiment. In this exemplaryembodiment only a first adhesive 1 is required, but the thickness of theadhesive is varied over the surface of the on-skin unit 44. For example,the adhesive is layered thickly at the left side of the on-skin unit 44and is increasingly thinly towards the right side. Thickness is a factorin skin adhesion and the duration which the adhesive may secure thesensor control device to a user's skin. Therefore, varying the thicknessof the adhesive over the on-skin unit 44 allows for balancing of thedifferent characteristics provided by different thicknesses.

Varying thicknesses of adhesive could also be used in the exemplaryembodiments with more than one adhesive. Also, the different adhesivepatterns disclose, including striped and concentric circles, could beused in any of the exemplary embodiments.

In another exemplary embodiment, shown in FIG. 16, microneedles are usedto help attach an on-skin unit 44 to the user. As shown in FIG. 16, themicroneedles 60 of the exemplary embodiment protrude from a bottomsurface of the sensor mount 45. The microneedles help attach the on-skinunit 44 to the user by being at least partially inserted into the user'sskin. The microneedles then catch or grab the user's skin, holding theon-skin unit 44 in place. In FIG. 16 the microneedles 60 are shownalone, without any adhesive. However, the microneedles 60 may also beused in combination with an adhesive. The microneedles 60 may protrudeat an angle in the range of 45° to 90° with respect to the sensor mount45 in accordance with the desire for balancing the strength of theattachment to the user's skin and the ease of insertion and removal ofthe microneedles 60 from the user's skin.

The on-skin unit 44 described in the above exemplary embodiments is notparticularly limited. In the exemplary embodiments, the on-skin unit 44comprises a sensor 42 and sensor mount 45 to which a transmitter 102 iscoupled. However, the on-skin unit adhered to the user's skin mayinclude elements other than those shown in the exemplary embodiments.For example, the on-skin unit 44 may comprise only a sensor.Alternatively, the on-skin unit 44 could include a variety of othercomponents which are part of an analyte monitoring system or othersystem.

Also, the exemplary embodiment of the disclosure has been described withrespect to an on-skin unit 44 for use with an analyte monitoring system100. However, the attachment structure and methods described above maybe applied to any of a variety of objects and devices which need to besecured, particularly those objects which need to be secured tosomeone's skin and which include a sensor or other device which shouldremain in the same place throughout an attachment. For example, thesecurement structures and methods described above could be applied toadditional or alternative portions of the analyte monitoring system 100.That is, in another embodiment all of the elements of the sensor controlelement 101 of the analyte monitoring system 100 would not necessarilyhave to be located on the user's skin. The present disclosure could beapplied to an inserted sensor without a transmitter 102. Furthermore,the attachment methods and structures described above could be appliedto devices other than elements of an analyte monitoring system such asan on-body insulin patch or infusion set/cannula of a pump system, orthe drug delivery patch of another type of drug delivery system, forexample, for pain medication, birth control, depression, etc.Particularly, devices for attachment to a person's skin. These devicesmay include at least a portion of an element, such as a sensor, insertedinto a person's skin.

A monitoring device element in one embodiment includes a mount, a firstadhesive on a surface of the housing and adapted to secure the mount tothe skin for a first time period, and a second adhesive on the surfaceof the housing and adapted to secure the mount to the skin for a secondtime period.

The first adhesive and the second adhesive may be arranged in analternating pattern, where the alternating pattern may includealternating stripes.

The monitoring device element may include at least one protrusionattached to the first adhesive, where the first adhesive is removablefrom the mount by pulling on the at least one protrusion.

In another aspect, the monitoring device element may include a removablecovering over the second adhesive, where when the removable covering isremoved, the second adhesive is exposed.

The monitoring device element may include at least one protrusionattached to the removable covering so that the removable covering isremoved by pulling on a second protrusion.

In another aspect, at least the second adhesive may be movable between araised position and a lowered position, where the second adhesive may beat the raised position during the first time period and at the lowerposition during the second time period.

The monitoring device element in still another aspect includes a glucosesensor mounted on the mount, at least one of a transmitter, receiver ortransceiver attached to the mount and coupled to the sensor.

A method in another aspect includes inserting a sensor at leastpartially into the skin, the sensor being supported by a sensor housing,securing the sensor housing to the skin with a first adhesive during afirst time period, and securing the sensor housing to the skin with asecond adhesive during a second time period, the second time periodbeing after the first time period, where the sensor remains at leastpartially inserted into the skin between the first time period and thesecond time period.

The method may include removing a covering to expose the second adhesivebefore securing the sensor housing to the skin with the second adhesive.

In another aspect, the method may include removing the first adhesiveafter the first time period.

Also, the method may include, between said first time period and saidsecond time period, lifting the sensor housing so that the firstadhesive no longer contacts the skin, removing the first adhesive toexpose the second adhesive, and lowering the sensor housing so that thesecond adhesive contacts the skin. Additionally, the method may includeswiveling the sensor housing before lowering the sensor housing so thatthe second adhesive contacts the skin at a different location than thefirst adhesive.

A monitoring device element in accordance with another aspect of thepresent disclosure includes a sensor at least partially inserted intoskin, a sensor housing supporting the sensor, the sensor housingcomprising a sensor area and a hinged area, a hinge hingedly connectingthe sensor area and the hinged area, and a first adhesive and a secondadhesive layered on a bottom surface of the hinged area, where the firstadhesive is adapted to secure the sensor housing to the skin during afirst time period and is removable, and where removing the firstadhesive exposes the second adhesive, the second adhesive being adaptedto secure the sensor housing to the skin during a second time period.

The monitoring device element may include a partition between the firstadhesive and the second adhesive, where the first adhesive is removedand the second adhesive is exposed by removing the partition.

In one aspect, the monitoring device element may include a thirdadhesive at a bottom surface of the sensor area, the third adhesivesecuring the sensor area to the skin.

The hinge in one aspect may allow the hinged area to rotate away fromthe skin.

In another aspect, the hinge may allow the hinged area to swivel aroundthe sensor area in a plane substantially parallel to the skin.

A monitoring device element in accordance with another aspect mayinclude a sensor adapted to be at least partially inserted into skin, ahousing which houses the sensor, a first adhesive and a second adhesiveprovided on a bottom of the sensor housing and being adapted to securethe sensor housing to a user's skin, where the first adhesive isstronger than the second adhesive, and further, where the first adhesiveand the second adhesive are formed in a pattern so that the firstadhesive contacts some areas of the skin and the second adhesivecontacts other areas of the skin.

The pattern may include concentric circles, or alternating stripes.

A monitoring device element in still another aspect may include a sensoradapted to be at least partially inserted into skin, a housing whichhouses the sensor, an adhesive provided on a bottom of the sensorhousing and being adapted to secure the sensor housing to a user's skin,where a thickness of the adhesive varies.

A device element in still yet another aspect includes a sensor mountsupporting a sensor, a plurality of microneedles protruding from thesensor mount and being adapted for insertion into a user's skin.

Accordingly, while non-limiting exemplary embodiments of the disclosurehave been described and illustrated above, it should be understood thatthese are examples of the disclosure and are not to be considered aslimiting. It will be understood by those of ordinary skill in the artthat additions, omissions, substitutions, and other modifications may bemade without departing from the spirit or scope of the presentdisclosure.

What is claimed is:
 1. A monitoring device element, comprising: a mount;a first adhesive on a surface of the mount and adapted to secure themount to a skin surface for a first time period; a second adhesive onthe surface of the mount and adapted to secure the mount to the skinsurface for a second time period; and a removable covering over thesecond adhesive; wherein when the removable covering is removed, thesecond adhesive is exposed; and further wherein the mount remainssecured to the skin surface during the removal of the removablecovering.
 2. The monitoring device element of claim 1, wherein the firstadhesive and the second adhesive are arranged in an alternating pattern.3. The monitoring device element of claim 2, wherein the alternatingpattern comprises alternating stripes.
 4. The monitoring device elementof claim 1, comprising: at least one protrusion attached to the firstadhesive; wherein the first adhesive is removable from the mount bypulling on the at least one protrusion.
 5. The monitoring device elementof claim 1, further comprising at least one protrusion attached to theremovable covering so that the removable covering is removed by pullingon the at least one protrusion.
 6. The monitoring device element ofclaim 1, wherein the second adhesive is movable between a raisedposition and a lowered position.
 7. The monitoring device element ofclaim 6, wherein the second adhesive is at the raised position duringthe first time period and at the lowered position during the second timeperiod.
 8. The monitoring device element of claim 1, further comprising:a glucose sensor; and communication unit attached to the mount andcoupled to the sensor.
 9. A method of attaching the monitoring deviceelement of claim 1, comprising: securing the mount to the skin surfacewith the first adhesive during the first time period, wherein the firstadhesive is positioned on the surface of the mount and adapted to securethe mount to the skin surface for the first time period; and securingthe mount to the skin surface with the second adhesive during the secondtime period, the second time period being after the first time period,wherein the second adhesive is positioned on the surface of the mountand adapted to secure the mount to the skin surface for the second timeperiod; and removing the removable covering positioned over the secondadhesive to expose the second adhesive before securing the mount to theskin surface with the second adhesive; wherein the mount remains securedto the skin surface during the removal of the removable covering. 10.The method of claim 9, further including inserting a sensor at leastpartially under the skin surface, the sensor being supported by a sensorhousing including the mount.